1. Field of the Invention
The present invention relates to an object detection device that irradiates a measured object with measurement light having a dot pattern, and detects the measured object based on reflected light.
2. Description of the Related Art
In Japanese Patent No. 5001286, an invention relating to an object detection device that detects a measured object using a coherent light source has been described.
In the object detection device described in Japanese Patent No. 5001286, an illumination region is irradiated with a random speckle pattern generated from the coherent light source, and light response from the illumination region is detected by an imaging unit. A difference in a speckle pattern between a pattern image obtained when the measured object moves to the illumination region and a reference image of the random speckle pattern when there is no measured object is detected, and a three-dimensional map of the measured object is built using a three-dimensional measurement method.
In the object detection device described in Japanese Patent No. 5001286, it is necessary to increase density of the dot pattern so as to detect a shape of the measured object in greater detail. However, when the density of the dot pattern increases, the number of dots for detection increases and accordingly, a processing load increases. Further, when movement of the measured object is detected using such a high-density dot pattern, processing does not keep up with a moving speed of the measured object due to a large number of detection dots. Accordingly, there is a problem in that, for example, the moving speed cannot be detected. Thus, in the object detection device, an optimum dot pattern varies depending on an item to be measured. However, in the object detection device of the related art, the optimal dot pattern according to each item cannot be prepared.